1. Field of the Invention
This invention relates to a pivot for pivotally supporting a structure over a child support or other support device. More particularly, the invention relates to a canopy pivot that is easily attached to a child's seat and rotates with respect thereto to provide adjustability for an attached canopy. In addition, the invention relates to a canopy pivot that is automatically lockable at a plurality of positions with respect to a child seat such that a canopy can be quickly and easily positioned relative to the child seat.
2. Description of Related Art
Adjustable canopies are available for a variety of support structures, including vehicles, chairs, strollers, baby carriers, child car seats and other child supports. The use of an adjustable canopy in children's support structures is particularly popular for the purpose of protecting an infant or child from different elements, including sun rays, wind and rain.
Typically, an adjustable canopy that is attached to a support structure includes a complicated mechanism for pivoting the canopy relative to the support structure. For example, U.S. Pat. No. 4,978,166 to James discloses a sunshade for a child's car seat that includes a locking pivot for adjusting the canopy. A screw 70 and cap 74 must be loosened so that each of the ribs 32, 34 and 36 can be adjusted with respect to each other and the car seat. To lock the ribs 32, 34 and 36 in position with respect to each other and the car seat, screw 70 and cap 74 must be manually turned and tightened while each of the ribs are held in position.
Another type of adjustable pivot is disclosed in U.S. Pat. No. 5,765,958 to Lan. The Lan device has a toothed wheel (retaining member 5) that floats in a first structure (stationary seat member 31) and second structure (pivotable seat member 4) to lock the first and second structures together when the toothed wheel is in a first position. The second structure can be pivoted relative to the first structure when the toothed wheel is pushed against the force of a return spring and out of contact with the second structure. Once the second structure is in a desired position, the toothed wheel is released to allow the return force of the return spring to reposition the toothed wheel into mating relationship with the second structure, thus locking the first and second structures in place. The Lan device is complicated to manufacture and assemble and requires a separate manual lock/unlock step for operating the pivot.
Attempts have been made to avoid the step of manually unlocking and locking a canopy or other structure in position relative to a support device. For example, two different inventions use cylindrical ratchet members to automatically lock and unlock a canopy pivot without requiring a separate step of loosening, retracting or unlocking the canopy pivot. In the first invention, U.S. Pat. No. 5,551,745 to Huang discloses an adjustable device for a hood of a toy stroller. The adjustable device includes a first side element 40 and a second side element 40'. Sandwiched in between the first and second side elements is a middle element 50 that is configured as a wheel having two cylindrical toothed portions divided by a plate portion 52. A toothed periphery 531 on each cylindrical portion mates with protrusions 43 and 43' located in the first and second side elements, respectively. When support element 20 is rotated about the adjustable device, protrusion 43' rides over the toothed portion 531 of the middle element 50. Protrusions 43' will lock into one of the spaces between the teeth of the toothed portion 531 to lock the support 20 in position with respect to the stroller when rotation of the support 20 is stopped. Support 10 can be similarly and separately moved and locked in position by the corresponding toothed surface 531 and protrusions 43.
The Huang device suffers from the drawback that the support members 10 and 20 must be made of relatively rigid material, for example metal, so that a requisite amount of force can be applied to unlock the adjustable device and rotate the support about the adjustable device. In addition, the adjustable device requires a plurality of separate structures and is fairly complicated to manufacture. The device is also susceptible to wear and tear since the teeth elements must flex for rotation to take place. Finally, smooth rotation of the support members does not occur because the mating toothed surfaces require the support member to vibrate and move back and forth in radial directions as the support member rotates about the adjustable device.
Similarly, U.S. Pat. No. 5,322,343 to Parker et al. discloses an adjustable canopy that includes a canopy stay 74 having a plurality of detents 78 therein that mate with a plurality of tangs 82 formed on a cylindrical protrusion from the car seat shell. The Parker device is simpler than that disclosed in Huang but suffers from many of the same drawbacks. Moreover, because the stay 74 must ride over each of the extending tangs 82, the radial motion of the stay 74 is not smooth when the position of the canopy is being changed. In addition, a high level of force is required to release the tangs 82 from the detents 78 and to rotate stay 74 with respect to the infant car seat. Finally, the reliability of the adjustment mechanism is low due to wear and tear on the tangs 82 over time.
Therefore, the industry lacks a canopy adjustment device with a reliable, easy to use, and durable pivot locking structure. In particular, a device is needed that is simple in structure and requires a minimum of moving parts. A device that does not require locking teeth to flex would provide certain advantages in wear and tear and durability. In addition, a device that smoothly rotates between adjustable positions and does not require a separate unlocking step is not known in the industry and would provide certain advantages over existing canopy pivots. For example, a device that does not vibrate or move in a radial direction while being unlocked and rotated is needed. In addition, it would be advantageous to require as little force as possible to rotate a canopy frame about the canopy pivot while allowing the canopy pivot to lock the canopy frame in place relative to a support structure when force is not applied to the canopy frame. Finally, a device that is economic and light weight while providing the above stated advantages would provide an improvement in the field of canopy pivots.